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Function in the stunted forelimbs of Mononykus olecranus (Theropoda), a dinosaurian anteater

Published online by Cambridge University Press:  08 April 2016

Phil Senter
Phil Senter*
Affiliation:
Department of Math and Science, Lamar State College at Orange, 410 Front Street, Orange, Texas 76630. E-mail: [email protected]
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Abstract

Mononykus olecranus, a theropod dinosaur from the Upper Cretaceous of Mongolia, exhibits reduced forelimbs with a single functional digit. These bizarre forelimbs have aroused great curiosity as to the behavior of the animal, but until now no functional study on the forelimbs of Mononykus has been undertaken. Here I show that the orientation and range of motion in the forelimb elements of Mononykus are such that the humeri sprawl laterally, the antebrachia are held subvertically, the palms face ventrally, and intramanual movement is restricted to subparasagittal motion. This is a radical departure from the typical theropod condition, in which the palms face medially and intramanual movement is transverse. The results of this study confirm that the forelimbs of Mononykus could not have been used to grasp prey or dig burrows, but were well suited for scratch-digging or hook-and-pull movements such as are used by extant anteaters and pangolins to open tough insect nests. Mononykus likely occupied a niche equivalent to that of an anteater or pangolin, an unusual niche for a dinosaur.

Type
Articles
Information
Paleobiology , Volume 31 , Issue 3 , Summer 2005 , pp. 373 - 381
Copyright
Copyright © The Paleontological Society 

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References

Literature Cited

Bonaparte, J. F. 1991. Los vertebrados fósiles de la Formación Río Colorado de la ciudad de Neuquén y cercanías, Cretácio Superior, Argentina. Revista del Museo Argentino de Ciencias Naturales (Bernardino Rivadavia), el Instituto Nacional del Investigación de las Ciencias Naturales, Paleontología 4:68–101.Google Scholar
Bonnan, M. F. 2003. The evolution of manus shape in sauropod dinosaurs: implications for functional morphology, forelimb orientation, and phylogeny. Journal of Vertebrate Paleontology 23:595–613.Google Scholar
Burnham, D. A., Derstler, K. L., Currie, P. J., Bakker, R. T., Zhou, Z., and Ostrom, J. H. 2000. Remarkable new birdlike dinosaur (Theropoda: Maniraptora) from the Upper Cretaceous of Montana. University of Kansas Paleontological Contributions 13:1–14.Google Scholar
Carpenter, K., and Smith, M. 2001. Forelimb osteology and biomechanics of Tyrannosaurus rex. Pp. 90–116in Tanke, D. H. and Carpenter, K., eds. Mesozoic vertebrate life. Indiana University Press, Bloomington.Google Scholar
Chiappe, L. M. 2002. The Cretaceous, short-armed Alvarezsauridae, Mononykus and its kin. Pp. 87–120in Chiappe, and Witmer, 2001.Google Scholar
Chiappe, L. M., and Coria, R. A. 2003. A new specimen of Patagonykus puertai (Theropoda: Alvarezsauridae) from the Late Cretaceous of Patagonia. Ameghiniana 40:119–122.Google Scholar
Chiappe, L. M., and Witmer, L. M., eds. 2001. Mesozoic birds: above the heads of the dinosaurs. University of California Press, Berkeley.Google Scholar
Chiappe, L. M., Norell, M. A., and Clark, J. M. 1996. Phylogenetic position of Mononykus (Aves: Alvarezsauridae) from the Late Cretaceous of the Gobi Desert. Memoirs of the Queensland Museum 39:557–582.Google Scholar
Chiappe, L. M., Norell, M. A., and Clark, J. M. 1998. The skull of a relative of the stem-group bird Mononykus. Nature 392:275–278.Google Scholar
Clark, J. A., Norell, M. A., and Makovicky, P. J. 2002. Cladistic approaches to the relationships of birds to other theropod dinosaurs. Pp. 31–61in Chiappe, and Witmer, 2001.Google Scholar
Emerson, S. B. 1976. Burrowing in frogs. Journal of Morphology 149:437–458.Google Scholar
Forster, C. A., Sampson, S. D., Chiappe, L. M., and Krause, D. W. 1998. The theropod ancestry of birds: new evidence from the Late Cretaceous of Madagascar. Science 279:1915–1919.Google Scholar
Frechkop, S. 1937. Sur les extrémités de l'oryctérope. Bulletin du Musée Royal d'Histoire Naturelle de Belgique 13:1–21.Google Scholar
Galton, P. M. 1971. Manus movements of the coelurosaurian dinosaur Syntarsus rhodesiensis and the opposability of the theropod hallux [sic.]. Arnoldia (Rhodesia) 5:1–8.Google Scholar
Gans, C. 1974. Biomechanics: an approach to vertebrate biology. Lippincott, Philadelphia.Google Scholar
Gauthier, J., and Gall, L. F., eds. 2001. New perspectives on the origin and early evolution of birds. Yale Peabody Museum, New Haven, Conn.Google Scholar
Gishlick, A. D. 2001. The function of the manus and forelimb of Deinonychus antirrhopus and its importance for the origin of avian flight. Pp. 301–318in Gauthier, and Gall, 2001.Google Scholar
Hildebrand, M. 1985. Digging of quadrupeds. Pp. 89–109in Hildebrand, M., Bramble, D. M., Liem, K. F., and Wake, D. B., eds. Functional vertebrate morphology. Harvard University Press, Cambridge.Google Scholar
Holliday, C. M., Ridgely, R. C., Sedlmayr, J. C., and Witmer, L. M. 2001. The articular cartilage of extant archosaur limb bones: implications for dinosaur functional morphology and allometry. Journal of Vertebrate Paleontology 21:62A.Google Scholar
Holtz, T. R. Jr. 1998. A new phylogeny of the carnivorous dinosaurs. Gaia 15:5–61.Google Scholar
Howe, D. 1975. Observations on a captive marsupial mole, Notoryctes typhlops. Australian Mammalogy 1:361–365.Google Scholar
Jenkins, F. A. Jr. 1993. The evolution of the avian shoulder joint. American Journal of Science 293-A:253–267.Google Scholar
Kardong, K. V. 2001. Vertebrates: comparative anatomy, function, evolution. McGraw-Hill, Boston.Google Scholar
Lehmann, W. H. 1963. The forelimb architecture of some fossorial rodents. Journal of Morphology 113:59–76.Google Scholar
Montgomery, G. G. 1983. Cyclopes didactylus (tapacara, serafin de platanar, silky anteater). Pp. 461–463in Janzen, D. H., ed. Costa Rican. University of Chicago Press, Chicago.Google Scholar
Nicholls, E. L., and Russell, A. P. 1985. Structure and function of the pectoral girdle and forelimb of Struthiomimus altus (Theropoda: Ornithomimidae). Palaeontology 28:643–677.Google Scholar
Norell, M. A., and Makovicky, P. J. 1999. Important features of the dromaeosaurid skeleton II: information from newly collected specimens of Velociraptor mongoliensis. American Museum Novitates 3282:1–45.Google Scholar
Norell, M. A., Chiappe, L., and Clark, J. 1993. New limb on the avian family tree. Natural History 102(9):38–42Google Scholar
Norell, M. A., Clark, J. M., and Makovicky, P. J. 2001. Phylogenetic relationships among coelurosaurian theropods. Pp. 49–67in Gauthier, and Gall, 2001.Google Scholar
Novas, F. E. 1996. Alvarezsauridae: Cretaceous basal birds from Patagonia and Gondwana. Memoirs of the Queensland Museum 39:675–702.Google Scholar
Novas, F. E. 1997. Anatomy of Patagonykus puertai (Theropoda, Avialae, Alvarezsauridae), from the Late Cretaceous of Patagonia. Journal of Vertebrate Paleontology 17:137–166.Google Scholar
Novas, F. E., and Pol, D. 2002. Alvarezsaurid relationships reconsidered. Pp. 121–125in Chiappe, and Witmer, 2001.Google Scholar
Novas, F. E., and Puerta, P. F. 1997. New evidence concerning avian origins from the Late Cretaceous of Patagonia. Nature 387–390–392.Google Scholar
Osmólska, H., Roniewicz, E., and Barsbold, R. 1972. A new dinosaur Gallimimus bullatus n. gen. n. sp. (Ornithomimidae) from the Upper Cretaceous of Mongolia. Palaeontologia Polonica 27:103–143.Google Scholar
Perle, A., Norell, M. A., Chiappe, L. M., and Clark, J. M. 1993. Flightless bird from the Cretaceous of Mongolia. Nature 362:623–626.Google Scholar
Perle, A., Chiappe, L. M., Barsbold, R., Clark, J. M., and Norell, M. A. 1994. Skeletal morphology of Mononykus olecranus (Theropoda: Avialae) from the Late Cretaceous of Mongolia. American Museum Novitates 3105:1–29.Google Scholar
Puttick, G. M., and Jarvis, J. U. M. 1977. The functional anatomy of the neck and forelimbs of the Cape golden mole, Chrysochloris asiatica (Lipotyphla: Chrysochloridae). Zoologica Africana 12:445–458.Google Scholar
Rahm, U. 1990. Modern pangolins. Pp. 630–641in Parker, S. P., ed. Grzimek's encyclopedia of mammals, Vol. 2. McGraw-Hill, New York.Google Scholar
Redford, K. H. 1985. Food habits of armadillos (Xenarthra: Dasypodidae). Pp. 429–437in Montgomery, G. G., ed. The evolution and ecology of armadillos, sloths, and vermilinguas. Smithsonian Institution Press, Washington, D.C.Google Scholar
Reed, C. A. 1951. Locomotion and appendicular anatomy in three soricoid insectivores. American Midland Naturalist 45:513–671.Google Scholar
Romer, A. S., and Parsons, T. S. 1986. The vertebrate body. Saunders College Publishing, Philadelphia.Google Scholar
Sereno, P. C. 1993. The pectoral girdle and forelimb of the basal theropod Herrerasaurus ischigualastensis. Journal of Vertebrate Paleontology 13:425–450.CrossRefGoogle Scholar
Sereno, P. C. 1999. The evolution of dinosaurs. Science 284:2137–2147.Google Scholar
Sereno, P. C. 2001. Alvarezsaurids: birds or ornithomimosaurs? Pp. 70–98in Gauthier, and Gall, 2001.Google Scholar
Slonaker, J. R. 1920. Some morphological changes for adaptation in the mole. Journal of Morphology 34:335–373.Google Scholar
Suzuki, S., Chiappe, L. M., Dyke, G. J., Watabe, M., Barsbold, R., and Tsogbaatar, K. 2002. A new specimen of Shuvuuia deserti Chiappe et al. 1998, from the Mongolian Late Cretaceous with a discussion of the relationships of Alvarezsaurids to other theropod dinosaurs. Contributions in Science, Natural History Museum of Los Angeles County 494:1–18.Google Scholar
Taylor, B. K. 1978. The anatomy of the forelimb in the anteater (Tamandua) and its functional implications. Journal of Morphology 157:347–368.Google Scholar
Taylor, B. K. 1985. Functional anatomy of the forelimb in vermilinguas (anteaters). Pp. 163–171in Montgomery, G. G., ed. The evolution and ecology of armadillos, sloths, and vermilinguas. Smithsonian Institution Press, Washington, D.C.Google Scholar
Walker, E. P., Hamlet, S. E., Lange, K. I., Davis, M. A., Uible, H. E., and Wright, P. F. 1975. Mammals of the world, 3d ed. Vol. 1. Johns Hopkins University Press, Baltimore.Google Scholar
Xu, X., Norell, M. A., Wang, X., Makovicky, P. J., and Wu, X. 2002. A basal troodontid from the Early Cretaceous of China. Nature 415:780–784.Google Scholar
Zhou, Z. 1995. Is Mononykus a bird? Auk 112:958–963.Google Scholar